The present invention relates generally to weld nuts and more particularly to an orientless weld nut.
Typical weld nuts have weld projections (small dimples that concentrate heat in controlled areas) on only one side. When the nut is welded to another component part, it is necessary to properly orient the nut so that the projections face the component part to which the nut is to be welded.
This need to correctly orient the nut causes manufacturing and welding problems. First the nut must be placed on the component part over a pin that centers it on a hole. This can be done manually or mechanically. If done manually, the nut is often incorrectly oriented due to human error. Even when done mechanically, errors can result. If the nut is applied upside down, the nut will either not weld to the component part at all, resulting in immediate failure of the weld, or the weld will be weak and fail in shipping or in use or when a threaded fastener is screwed into the nut. This failure leads to high repair, scrap, and inspection costs.
If the nut is located mechanically, there is an increased cost of equipment and maintenance. The mechanical devices used must orient and locate the nut. This can cause problems. Mechanical devices used to accomplish this include bowl feeders and rod type nut feeders. If the bowl feeder is dirty or improperly adjusted, the nuts can jam or be delivered upside down. If the pin wears or the rod type feeder is bent, worn or improperly adjusted, the nut can be mislocated off the pin. All of these problems will drive up the costs of maintenance, quality, inspection, repair and scrap, which have been traditionally high.
The orientless nut of this invention simplifies the entire process. The nut has weld projections on both sides. The nut can still be located manually or mechanically. There is no longer a risk that the nut can be placed upside down. As long as the nut is on the locating pin, the weld will be good.
One consideration that must be addressed to use the orientless nut involves the upper electrode that contacts the nut. The upper electrode must be recessed to provide clearance for the projections on the topside of the nut. Otherwise, the projections on the topside of the nut may weld to the electrode.
One object of this invention is to provide a weld nut having the foregoing features and capabilities.
Another object is to provide a method of welding a nut to a component part.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.